Transparent thermoplastic resin pellet manufacturing method

Abstract

A method for producing a transparent thermoplastic resin pellet comprising a step of kneading a transparent thermoplastic resin with a kneader under a condition under which a damage history calculated according to the following formula is 500 to 2,500:Damage history={Residence time (tr)}×{Shear rate (γ)}Residence time (tr)=(W×H×L) / Q Shear rate (γ)=(π×D×N) / H in the formulae, W represents a screw groove width (pitch) [cm]; H represents a screw groove depth [cm]; L represents a screw length [cm]; Q represents a resin supply amount [g / s]; D represents a screw diameter [cm]; and N represents a screw rotation number [rps].

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for manufacturing a transparent thermoplastic resin pellet, and in particular, the present invention relates to a method for manufacturing a pellet of a transparent thermoplastic resin such as a polycarbonate resin, etc.BACKGROUND ART

[0002] In recent years, transparent thermoplastic resins such as polyarylate resins, polymethyl methacrylate resins, polystyrene resins and polycarbonate resins are preferably used as a molding material in the optical field. In these applications, the size or amount of foreign matter (e.g., dusts, carbides, gelled products, etc.) in the resin, and whether the hue of the resin is good or bad largely influences the quality of the product. In particular, in the manufacture of an optical light guide plate, a change of hue of the resin constituting a substrate and a foreign matter in a substrate give an extremely large influence against the reliability of the product.

[0003] In a method of obtaining...

Examples

reference example 1

[0051]For reference, molding was conducted by using a polycarbonate resin PC-1 not having been passed through a twin-screw kneader, and the YI and number of gels were measured. Results are shown in Table 2.

examples 1 to 11

, Comparative Examples 1 to 5, and Reference Example 2

[0052]A polycarbonate resin, a twin-screw kneader, and a screw shown in Table 2 were used, the polycarbonate resin was charged into the twin-screw kneader under a condition shown in Table 2, and kneading was conducted by properly setting a cylinder temperature of the twin-screw kneader to an appropriate value in conformity to fluidity of the resin, thereby producing a polycarbonate resin pellet. Molding was conducted by using the obtained polycarbonate resin pellet, and the YI and number of gels were measured. Results are shown in Table 2.

[0053]

TABLE 2ReferenceComparativeComparativeExample 1Example 1Example 1Example 2Polycarbonate resinPC-1PC-1PC-1PC-1Viscosity average17,00017,00017,00017,000molecular weight MvTwin-screw kneader No.—111Screw type—AAAScrew diameter D[mm]—373737Resin supply amount Q[kg / h]—202020Screw rotation number N[rpm]—100200160Q / N—0.200.10.125Residence time tr[sec]—39.239.239.2Shear rate γ[sec−1]—52.4104.783.8...

TECHNICAL FIELD

[0001] The present invention relates to a method for manufacturing a transparent thermoplastic resin pellet, and in particular, the present invention relates to a method for manufacturing a pellet of a transparent thermoplastic resin such as a polycarbonate resin, etc.BACKGROUND ART

[0002] In recent years, transparent thermoplastic resins such as polyarylate resins, polymethyl methacrylate resins, polystyrene resins and polycarbonate resins are preferably used as a molding material in the optical field. In these applications, the size or amount of foreign matter (e.g., dusts, carbides, gelled products, etc.) in the resin, and whether the hue of the resin is good or bad largely influences the quality of the product. In particular, in the manufacture of an optical light guide plate, a change of hue of the resin constituting a substrate and a foreign matter in a substrate give an extremely large influence against the reliability of the product.

[0003] In a method of obtaining...

Examples

reference example 1

[0051]For reference, molding was conducted by using a polycarbonate resin PC-1 not having been passed through a twin-screw kneader, and the YI and number of gels were measured. Results are shown in Table 2.

examples 1 to 11

, Comparative Examples 1 to 5, and Reference Example 2

[0052]A polycarbonate resin, a twin-screw kneader, and a screw shown in Table 2 were used, the polycarbonate resin was charged into the twin-screw kneader under a condition shown in Table 2, and kneading was conducted by properly setting a cylinder temperature of the twin-screw kneader to an appropriate value in conformity to fluidity of the resin, thereby producing a polycarbonate resin pellet. Molding was conducted by using the obtained polycarbonate resin pellet, and the YI and number of gels were measured. Results are shown in Table 2.

[0053]

TABLE 2ReferenceComparativeComparativeExample 1Example 1Example 1Example 2Polycarbonate resinPC-1PC-1PC-1PC-1Viscosity average17,00017,00017,00017,000molecular weight MvTwin-screw kneader No.—111Screw type—AAAScrew diameter D[mm]—373737Resin supply amount Q[kg / h]—202020Screw rotation number N[rpm]—100200160Q / N—0.200.10.125Residence time tr[sec]—39.239.239.2Shear rate γ[sec−1]—52.4104.783.8...

Images